Hyundai Repair: Check Engine light on Hyundai Elantra 1996, hyundai elantra, charcoal canister

Question
I recently bought a used Hyundai Elantra 1996 1.8 L. It runs well. After purchasing the car, Check Engine light came up. I got the error code checked at Autozone.It is P0446.I need to remove that 'Check Engine' light before I go for inspection sticker. Please suggest what can be its root cause and how to rectify it? Thanks in advance .. Regards

Answer
The most common cause of this code on the 1996 Elantra is a stuck open purge control valve.  But in reality, there are a number of possible causes.  What the code means is that there's excessive vacuum in the fuel tank.  If the purge control valve is stuck open, it'll apply engine vacuum to the fuel tank faster than the tank can receive air from the atmosphere.

One possibility is that the fuel tank pressure sensor is giving erroneous readings.  But it's also possible that there's some sort of restriction preventing the tank from obtaining air from the atmosphere.  This could be in the charcoal canister, the canister filter, the valves in the fuel tank, or any of the plumbing in the evaporative system between the fresh air intake and the fuel tank.

If you're okay taking a guess, you might try replacing the purge control valve.  Beyond that, I'd recommend having the problem diagnosed by either the dealer or a top notch driveability shop.